Improvement in burglar-alarms



W. BRUEN & T. E. PRICE.

BURGLAR-ALARM.

Patented Jan. 11,1875.

No.17Z,08Z.

UNITED STATES PATENT QFFIOE.

WILLIAM BRUEN AND THOMAS E. PRICE, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 172.082; dated January 11, 1876; application filed October 27, 1875.

companying drawing, which forms a part of this specification, in which- Figure 1 is a longitudinal section',-and Fig. 2 a side elevation.

To enable those skilled in the art to which our invention relates the better to understand and construct the same, we will describe it more fully.

In Fig. 1, B is the base, which may be made of cast or-sheet metal, andis provided on its upper surface with the lugs Z, two of them standing opposite each other, between which the hammer h is hung on the rivet r, Fig. 2. The hammer his provided at its rear end with a recess or chamber, within which there is coiled the spring S, which actuates the hammer. The rivet r, passing through the lugs l, and that portion of the hammer which forms the sides of the chamber, and within the coils of the spring S, holds the whole together and forms the fulcrum'upon which the hammer swings. Instead of the chamber, however, this portion of the hammer may be reduced to a shaft, with the coil around it instead of within it, but in that case the spring would be exposed to view, which objection is now avoided. In the rear of the hammer h, and just back of the lugs I, there are two other smaller lugs, 1, between which is pivoted the trigger t, which is S-shaped, the upper end of which forms a catch, 0, which holds thehammer back when set and'in use, and the lower end of which projects backward, forming the fin ger-piece, against which the door or window strikes when an attempt is made to open them from without, and as the lower end is carried forward the catch G is disengaged from the arm a, when, by the action of the spring S,

the hammer h, provided with the pivot P, is

driven upon the cap or cartridge on the nipple a with sufficient force to explode it, and the inmates of the house are'awakened thereby. Between the lugs I there is an opening through the base for the double purpose of lessening the weight and facilitating the operation of placing the spring in position in putting the alarm together. One end of the spring S projectsthroughthe said opening at e, abutting against the edge of the base, whereby it is held in a taut or strained position. At the forward end of the base B, and directly under the nipple a, there is a spur, S, projecting downward into the floor when the alarm is set, thus preventing the door or window, as the case may be, from being opened from the outside in case the cap should prove to be worthless and not explode' The rear end of the base at w is wedge-shaped, to enable it the more readily to enter between the door and threshold. at is an arm, projecting from the chambered portion of the hammer,

which engages with the catch 0 when the alarm is set, as shown in Fig. 2. The alarm may be applied with equal facility and advantage between the upper and lower sash of a window, with the spur S engaging with the inner surface of the upper sash.

The advantages of our invention are, that while it serves to alarm the household it also securely prevents opening the door or window 1 from the outside; and, further, its simplicity renders it very cheap.

Having thus described our invention, what WILLIAM BRUEN. THOMAS E. PRICE. Witnesses:

HENRY O. HUNT, ELwoon O. HARRIS. 

